We just purchased a Novatel USB551L for connecting our Balance 20 to Verizon Wireless in a failover situation. Initially I could not get the modem to connect. It was only after I upgraded the firmware to the latest version the modem immediately connected.
I probably should have thought of this upfront - but it would be a good idea for the Peplink user manual to call this out. The troubleshooting section doesn’t mention to download the latest firmware as part of any troubleshooting exercise.
Good one Jeff! Yes in fact upgrading to the latest firmware should be the first step of any troubleshooting. Let’s me see how we can append this to our existing materials. Thanks Jeff 
Thank you. I would suggest a mention in 11.1.5 Mobile Internet Connection - possibly explaining modem parameters are downloaded via the firmware and therefore the latest firmware should be downloaded to ensure a smooth implementation.
Also http://www.peplink.com/3g - this section mentions the ‘keeps Connecting’ status at the bottom of the page. Old firmware should be in the bullet point reason list.